Manufacture of elastic fabrics



March 1940- F. F. SCHWARTZ ET AL 2,193,496

MANUFACTURE OF ELASTIC FABRICS Filed April 16, 1937 q 1 nnnnnhhuhur. I h o Patented Mar. 12, 1940 u ,iTED STATES PATENT OFFICE A MANUFACTURE OF ELASTIC FABRICS Application April 16, 1937, Serial No. 137,254

I In France January 26, 1937 8 Claims.

In United States patent application Serial No. 112,972 there is described a novel rubberised fabric which is not only very porous but also possesses in high degree resistance to deformation. Thus, for example, temporary elongation of the fabric is only brought about by the exertion of a considerable force. The process for the production of such a fabric consists in applying rubber or other elastic substance to the 10 surface of a knitted or woven fabric in such a way as to leave the threads free to slide relatively to one another at their points of intersection in spite of their union with the rubber. This. result is obtained by projecting latex on to 5 the knitted or woven fabric by means of sprayers and by carrying out the operation so that the latex is deposited only on the projecting or salient portions of the knitted or woven fabric where it forms a network, the design of which corresponds to that of the said projecting or salient portions.

In order to achieve this result the various factors of the spraying operation are suitably regulated and in particular the latex is applied in a number of very thin successive coatings, each coating being dried before the succeeding coating is applied. In this way, the latex par ticles are deposited on the projecting or salient portions of the fabric and build up a network 80 which while tenaciously adhering to the fabric is present only on the surface of the said fabric.

As most knitted or woven fabrics do not possess projecting or salientelements capable of assisting the formation of a network of the desired type from rubber latex the present applicants have described in their co-pending United States patent application Serial No. 112,973 a process for forming upon a knitted or woven fabric projecting or salient portions on which the latex is deposited during spraying. The said process consistsessentialiy in treating fabrics so as to impart to the surface which is subsequently to be coated with rubber latex projecting or salient portions of the desired form, relief and disposition. One methodof carrying out that process consists in submitting the woven or knitted fabric to an embossing operation, this embossing being produced inter alia by the aid of an engraved cylinder. y

In order to enable the woven or knitted fabric to preserve the imprints produced by this embossing until the fabric has been subjected to the subsequent process of spraying with rubber latex or the like, provision was made in the abovementioned application to make use of a dressing sprayers on to the face of the fabric opposite to serving to stiffen the fabric, and adapted to be hardened, e. g., by the influence of heat which may be applied during the embossing operation itself.

The present invention relates to an alternative 5 means for maintaining the knitted or woven fabric in the form given to it by the embossing treatment during the subsequent operations necessary for forming the deposit of latex on the embossed surface. This means consists essentially in sticking the knitted or woven fabric, e. g., to a thin sheet of paper so that the composite sheet is capable of preserving impressions made thereon for example by embossing, crimping or like operation and in subjecting the composite sheet consisting of knitted or woven fabric and paper to the action of means intended to V produce thereon the desired prominences or projections. Tests have shown that such a com- .posite sheet retains perfectly the form given to it in the embossing operation.

The woven or knitted fabric stuck to its support and embossed is then subjected to spraying, that is to say latex is projected by means of that which is stuck to the paper, i. e., on to the exposed face of the fabric. This spraying is effected under the conditions already described in the above-mentioned United States patent applications, for example by making successive applications of very thin layers and subjecting each deposit of particles to a drying operation before applying the next layer.

The present invention not only possesses the advantage that the fabric is maintained in its embossed or deformed state but in addition it prevents passage of the latex through the fabric when the latter is of an open nature. When knitted or woven fabrics of wide meshes or very open structure are employed, it may happen that the latex passes through the fabric and alters the appearance of the uncoated face, whereas the latter should retain its original appearance. This disadvantage is obviated by the process according to the invention. a

When the desired thickness of rubber has been deposited, the knitted or woven fabric is separated from the paper or other layer which I has served as a temporary backing or support.

If the paper or other backing has been stuck only lightly'to the fabric, it is merely necessary to pull the paper in order to detach it. If on the other hand the adhesion between the two is firmer, the paper may be detached from the fabric by moistening with water or other'liquid.

It is known in the art of embossing materials to stick, e. g., a textilematerial on to paper, but this method of procedure is only intended to ensure a correct introduction of the material into the embossing or like machine. In the present process, on the contrary, the combination of the paper with the knitted or woven fabric is intended to compel the latter to retain during the subsequent steps of the process necessary for applying the coating of latex the form imparted to it by the embossing or like operation. In general, the fabric itself unless sup-, ported by a backing would not be capable of undergoing the spraying treatment without partly or wholly losing the prominences formed in the embossing operation whereas when on its paper support, the fabric is able to resist the various actions to which it is subjected prior to or during the spraying operation.

The support employed for the fabric may consist not-only of any of the various substances designated under the name of paper but may alternatively consist of any composition capable of performing an equivalent function. Thus, a sheet or layer of fibrous material or a plastic substance or a mixture of these materials may be used. Again, the backing may consist of a layer of paste or size.

By way of example it may be stated that a suitable substitute for the paper is soluble starch paste. After the formation of the latex deposit on the exposed face of the fabric, it is easy to remove this paste by the action of water in the presence of a diastase.

The sheet of paper or other equivalent material may beprepared beforehand and stuck to the fabric, as has just been described. It may also be formed directly on the knitted or woven fabric itselfand in this case it may be applied by any appropriate means, for example by means of knives, sizing machines, sprayers etcetera. It will be understood that the necessary precautions should be taken so that the adhesion between the layer thus formed and the fabric will not be too great in order that they may subsequently be easily separated. For this purpose it is possible to interpose between the fabric and the support or backing layer an intermediate layer of material for example a soluble material which may afterwards be caused to disappear and thus permit the separation of the fabric and the backing.

In the foregoing, it has been supposed that the formation of the projections on the fabric is produced by embossing. Accor ding to the invention, the projections may be produced by other means including those described in United States specification Serial No. 112,973. It is possible for example to employ known processes for effecting the shagreening or creping of materials and fabrics, which consist in forming the fabrics of combinations of threads of different nature, some of which are capable of shrinking under certain conditions;

In certain cases it may be desired to form parallel threads or bars of rubber on a knitted fabric instead of a network of crossing threads.

This is the case, for example, when the fabric has to support stresses only in-one direction. The embossing member is then constructed accordingly and is provided with parallel ribs which imprint similar ribs in the fabric. The embossing member then forms a series of parallel ridges and the embossing is reduced to a pleating. According to the invention it is possible to effect the formation of these pleats by any of the means known for effecting the pleating of fabrics.

Following is a description by way of example only and with reference to the accompanying diagrammatic drawing of methods of carrying the invention into effect.

In the drawing, in which similar reference nil-- bossing. The fabric II with its attached backing I2 is supported on a resilient surface It and is subjected to embossing pressure by means of an embossing roller l5. After embossing, the fabric and its backing form projections such as I 6.

Figure 5 shows an alternative method of deforming the composite layer by crimping in which two fluted rollers (portions of which are shown at I1 and I8) impart corrugations, as at l9 to the composite sheet of fabric and backing. After the embossing or like operation has been applied to the fabric and its backing, the exposed surface of the fabric is sprayed with rubber latex from a spray gun 2U (asshown in Figure 6) and between the application of successive coatings of latex the latex 2| is dried as indicated in Figure '1 in which the hood of the drying chamber is shown at 22.

After the spraying operation has been completed the backing may be removed from the fabric either by stripping dry or by applying water or other liquid as shown in Figure 8 in which water contained in a trough 23 is applied to the backing by means of the roller 24.

Figure 9 shows an alternative method of forming a backing on a fabric l I by spraying the material of which the backing 25 is composed from a spray gun 26.

Figure 10 shows the application of a plastic backing material 21 to the surface of a fabric H by means of apparatus consisting essentially of an extrusion nozzle 28 and a pair of rollers 29 and 30, the apparatus being passed over the stationary fabric or the fabric being moved under the stationary coating apparatus.

We claim:

1. A process for the manufacture of an elastic fabric which comprises temporarily providing a knitted or extensible woven textile fabric on one of its surfaces with an effectively adhering backing layer which renders the composite sheet capable of receiving and retaining impressions made thereon, deforming the composite sheet to bring selected portions of the fabric into relief,

applying to the deformed surface of the fabric \an aqueous dispersion of rubber by spraying, drying and coagulating the said coating and removing the backing layer from the fabric.

2. A process for the manufacture of an elastic fabric which comprises temporarily providing a knitted or extensible woven textile fabric on one of its surfaces with an effectively adhering backing layer which renders the composite sheet capable of receiving and retaining impressions made thereon, deforming the composite sheet to bring selected portions of the fabric into reduring a very short time, coagulating and drying the latex and repeating the spraying and dry-- ing operations in order that the latex may deposit principally on the projecting portions of the surface of the fabric and removing the backing layer from the coated fabric.

3. A process for the manufacture of an elastic fabric which comprises temporarily providing a knitted or extensible Woven textile fabric on one of its surfaces with an effectively adhering sheet of paper which renders the composite sheet capable of receiving and retaining impressions made thereon, deforming the composite sheet to bring selected portions of the fabric into relief, spraying the exposed surface of the fabric with rubber latex in order that the latex may deposit principally on the projecting portions of the surface of the fabric and removing the sheet of paper from the coated fabric. A

4. A process for treating a knitted or extensible woven textile fabric with rubber latex which comprises temporarily but effectively uniting one surface of the said textile fabric with a fibrous backing layer by means of a readily removable intermediate layer, subjecting the fabric surface of the composite sheet to deformation so as to bring selected portions of the said surface into relief, applying rubber latex t0 the exposed surface of the fabric in the form of a. finely divided spray, coagulating and drying the latex deposit and subsequently removing the fibrous backing layer from the coated fabric.

5. A process for treating a knitted or extensible woven textile fabric with rubber latex which comprises temporarily but effectively uniting one surface of the said textile fabric to a sheet of paper by means of a water-soluble adhesive, subjecting the composite sheet to pleating, applying a plurality of thin layers of rubber latex in the form of a spray to the exposed fabric surface of the composite pleated sheet, each layer of rubber being coagulated and dried prior to the application of the succeeding coating, and thereafter removing the paper backing from the coated fabric.

6. A process for the manufacture of elastic fabric which comprises temporarily providing a knitted or extensible woven textile fabric on one of its surfaces with an effectively adhering backing layer of fibrous material which renders the composite sheet capable of receiving and retaining impressions made thereon, deforming the composite sheet to bring selected portions of 'the fabric into relief, applying to the deformed ders the composite sheet capable of receiving and retaining impressions made thereon, deforming the composite sheet to bring selected portions of the fabric into relief, applying to the deformed surface of the fabric an aqueous dispersion of rubber by spraying, drying and coagulating the said coating and removing the backing layer from the fabric.

8. A process for the manufacture of an elastic fabric which comprises temporarily providing a knitted or extensible woven textile fabric on.one of its surfaces with an effectively adhering backing layer which renders the composite sheet capable of receiving and retaining impressions made thereon, embossing the composite sheet to bring selected portions of the fabric into relief, applying to the deformed surface of the fabric an aqueous dispersion of rubber by spraying,

drying and coagulating the said coating and removing the backing layer from the fabric.

FERNAND FREHJERIC SCHWARTZ. MARC. ALFRED CHAVANNES. 

